#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <cstdlib>


#ifndef __cplusplus
typedef bool unsigned char;
#define true 1
#define false 0
#endif

const char OPERATOR_OR  = '|';
const char OPERATOR_AND = '&';
const char OPERATOR_NOT = '!';
const char OPERATOR_XOR = '^';

const char ASCII_A = 0x41;
const char ASCII_Z = 0x5A;


static unsigned char *variables;
static unsigned char varsCount;


/*
 * Decide how many variables are in string
 *
 * @param string
 */
unsigned char getVarsCount(const char *string)
{
    unsigned char i;

    if ( string == NULL )
        return 0;

    for ( i = ASCII_A; i < ASCII_Z; i++ )
    {
        if ( strchr(string, i) == NULL )
            return ( i - ASCII_A );
    }

    return 0;
}

/*
 * Get var's current value by char represent.
 *
 * @param var
 */
unsigned char getValue(const char var)
{
    return ( variables[var - ASCII_A - 1] );
}



/*
 * Parses the sequence of strings and returns
 * Stack, packed in char array (zero-ended)
 *
 * @param string - input string
 */
unsigned char parseString(char *string)
{
    size_t length;
    int    i;
    int    value_total;

    if ( string == NULL )
        return NULL;

    // Get stack length
    length = strlen(string);
    if ( length < 1 )
        return 0;

    value_total = getValue(string[0]);

    // Parse the string
    for ( i = 1; i < length; i++ )
    {
        if ( string[i] == OPERATOR_AND )
            value_total &= getValue(string[i + 1]);
        else if ( string[i] == OPERATOR_OR )
            value_total |= getValue(string[i + 1]);
        else if ( string[i] == OPERATOR_XOR )
            value_total ^= value_total;
        else if ( string[i] == OPERATOR_NOT )
            value_total = ! value_total;
    }

    return value_total;
}


/*
 * The entry point
 *
 * @param argc - cl arguments count
 * @param argv - cl arguments 2d array
 */
int main(int argc, char **argv)
{
    FILE *fp = NULL;
    char string[256];
    char tmp_string[256];
    unsigned char i;
    size_t count;

    fp = fopen("expression.txt", "r");
    if ( fp == NULL )
        return 1;

    count = fread(string, 1, 255, fp);
    fclose(fp);

    string[count] = 0x00;
    printf("Expression: %s\n\n", string);

    fopen("output.txt", "w");


    for ( i = 0; i < varsCount; i++ )
    {

    }

/////////////////////////////////////////////////////////////////
// Вот тут надо переберать переменные и вызывать parseString
/////////////////////////////////////////////////////////////
//  fwrite(tmp_string, 1, strlen(tmp_string), fp);

    varsCount = getVarsCount(string);
    printf("%d\n", varsCount);

    fclose(fp);

    system("PAUSE");
    return 0;
}